50-year old Epstein was born into a working-class Brooklyn family, and attended the city’s Lafayette High School. In his early ’20s, he taught mathematics and physics to high school students at The Dalton School, an elite Manhattan preparatory school.

Epstein began his career in high finance at Bear Stearns, where he ascended the ranks to become a limited partner before leaving in 1981 to open his own business.

Shortly thereafter, he founded J. Epstein & Co., a private holding company, which he has been running ever since.

Although Epstein chooses only to manage the money of billionaires, including Wexner, a source familiar with Epstein’s business dealings says the choice does not indicate any hubris on his part.

“It’s not by reason of arrogance,” the source says. “Many people can manage $100 million. Managing $1 billion requires a totally different skill set.”

And it seems Epstein believes he is providing an important service to his incredibly wealthy, and therefore incredibly vulnerable, clients.

“The burden of wealth is often not very well thought out,” the source says. “These people couldn’t imagine their wealth. They have a [Chief Financial Officer], an accountant and stockbrokers, and their financial lives start to look like a house that is added onto every year. At the end it doesn’t work very well.”

His client list is a closely-guarded secret, bar one: Wexner is a long-time client. He is also Epstein’s mentor.

Indeed, friends say his close relationships with Wexner and others have provided him with a brand of informal education.

Epstein briefly studied physics at The Cooper Union for the Advancement of Science and Art in New York and New York University’s Courant Institute of Mathematical Sciences but never graduated from either.

Sources close to Epstein say he found the traditional college environment stifling.

But Epstein has never approached learning and living conventionally.

From flying President Clinton, Kevin Spacey and Chris Tucker to Africa to explore the problems of AIDS and economic development facing the region, to hosting the world’s elite minds at his lavish homes in New York, Palm Beach, New Mexico and his private island hideaway, to funding outreach programs to curb the spread of Cholera in Bangladesh, it seems Epstein lets his curiosities guide him.

Friends say Epstein’s scientific, intellectual and philanthropic interests—not his host of homes or his fleet of aircraft—give him the most satisfaction.

And over the past decade, those interests have consistently—and increasingly—led him to Harvard.